Semiconductor component, in particular a solar cell, and process for manufacture of same The invention concerns a semiconductor component, in particular a solar cell, with at least one semiconductor base material consisting of a mono or a polycrystalline structure, which consists at least in part of pyrite with the chemical composition FeS2 and which is cleaned for the purpose of achieving a defined degree of purity.
A number of generic semiconductor components or semiconductor photocomponents are already recognized which, given an efficiency level of approximately 15%, are used commercially on the basis of the internal photo effect of radiation energy from the sun or from light. Thin silicon or gallium arsenide iron crystal with p and n conductive zones are used predominantly as semiconductor materials.
Thin-layered solar cells are also recognized, in the case of which the semiconductor layers are positioned on a carrier by means of metallization or similar to produce a thickness in the range of micrometers (1 to 50 xcexcm). Materials such as cadmium sulphide, cadmium telluride, copper sulphide or similar are used for the semiconductor layers. These semiconductor components are only able to achieve an efficiency of 5-8%. However, they have a useful power-weight ratio and are essentially more cost-effective to produce than silicon-iron crystals.
According to Patent Specification EP-A 0 173 642, a generic solar cell is a photo-active pyrite layer with the chemical formula FeS2+/xe2x88x92x, which has a concentration of undesirable impurities of  less than 1020 per cm3 and a dopant of manganese (Mn) or arsenic (As) and/or cobalt (Co) or chlorine (Cl). In practice, it would appear that a solar cell with this composition cannot achieve the required efficiency level.
In contrast, the object of this invention is to create a semiconductor component, in particular a solar cell on the basis of the type mentioned above which can be used to achieve a higher efficiency than the known sun or light radiation. Furthermore, the production costs in respect of this semiconductor component will be sufficiently low that this type of solar cell would be suitable for mass production. A further object of the invention exists in using a semiconductor material which can be disposed of easily in an environmentally friendly manner.
The invention is able to meet the objective in that the semiconductor base material which consists at least in part of pyrite with the chemical composition FeS2, is combined or doped at least with boron and phosphorus respectively.
With a very advantageous type, the semiconductor base material is produced from at least one layer of pyrite together with the elements boron and phosphorus. Used in this way, an optimum and extremely efficient composition is achieved, especially for solar cells.
These semiconductor components in accordance with the invention can be used to produce solar cells which have a higher efficiency than any other known solar cells. The pyrite used as a semiconductor material has the advantage of being a natural material which can also be produced synthetically. The production costs can be kept to a level such that, given the increased level of efficiency, profitable use can be drawn.